Dresden 2026 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 27: Focus Session: Tunable Correlations in van der Waals Quantum Materials II (joint session TT/DS/HL)

TT 27.2: Vortrag

Dienstag, 10. März 2026, 10:00–10:15, HSZ/0105

Engineering Hubbard models with gated two-dimensional moiré systems — •Yiqi Yang¹, Yubo Yang², Miguel Morales³, and Shiwei Zhang³ — ¹Lund University, Lund, Sweden — ²Hofstra University, New York, USA — ³Flatiron Institute, New York, USA

Lattice models are powerful tools for studying strongly correlated quantum many-body systems, but their general lack of exact solutions motivates efforts to simulate them in tunable platforms. Recently, a promising new candidate has emerged for such platforms from two-dimensional materials. A subset of moiré systems can be effectively described as a two-dimensional electron gas (2D EG) subject to a moiré potential, with electron-electron interactions screened by nearby metallic gates. In this talk, we present the realization of lattice models in such systems [1]. We show that, by controlling the gate separation, a 2D EG in a square moiré potential can be systematically tuned into a system whose ground state exhibits orders analogous to those of the square lattice Hubbard model, including the stripe phase. Furthermore, we study how variations in gate separation and moiré potential depth affect the ground-state orders. A number of antiferromagnetic phases, as well as a ferromagnetic phase and a paramagnetic phase, are identified.We then apply our quantitative downfolding approach to triangular moiré systems closer to current experimental conditions, compare them with the square lattice parameters studied, and outline routes for experimental realization of the phases.
[1] arXiv:2508.13314

Keywords: Twistronics; Quantum many-body systems; Two-dimensional electron gas; Hubbard model; Density functional theory